RUPERT, Idaho — Engineering is underway on an irrigation district’s plan to build a pumping plant and pipeline to supplement rapidly declining wells with surface water in an overtaxed portion of the Eastern Snake Plain Aquifer.
A & B Irrigation District hopes to pipe 4,500 acre feet to supplement about 1,500 groundwater-irrigated acres with surface water, in years when surface water is available. The district, which supplies water to 65,000 acres of well-irrigated land and 17,000 surface-irrigated acres in Jerome and Minidoka counties, expects the pipeline will make it possible to shut down six to eight under-performing wells. The wells could still be used if no surface water rights are found to supply the new pipeline.
The pipeline will also supply additional water to 4,500 acres of farm land that are currently irrigated by surface water but haven’t been getting adequate deliveries during peak months. A & B manager Dan Temple explained the current canal has had additional constraints on it since the mid-1990s, when the district abandoned other declining wells and switched to surface water.
The USDA’s Natural Resources Conservation Service is doing the design work on the planned pipeline and pumping plant and has awarded the project $3.8 million in funding previously made available by the former Agricultural Water Enhancement Program for water conversion projects. Earlier this fall, the Idaho Water Resources Board also approved a $7 million loan for the project. Temple said construction should commence next fall, with the goal for completion by 2016. The pipeline will divert water 8 miles west of Burley and run 8 miles perpendicular to the Snake River.
Temple said A & B may use some of its current 137,000 acre feet of storage, rent from the Water District 1 Rental Pool or lease other user’s storage to supply the pipeline.
Temple said the level of the aquifer’s western portion has dropped 19 feet since 1999. Three years ago, the district spent $2 million to purchase its own rotary drill rig and added a licensed driller to its staff to deepen some of its 180 active wells.
“We have been drilling nonstop, and we’re not done yet,” Temple said.
He said they’ve also invested about $20 million “chasing water” since 1990, and the district pursued a failed water call against junior groundwater users.
Heyburn farmer Clay Harrison, a surface water irrigator, said inadequate peak-season irrigation deliveries from the overburdened existing canal have affected his malt barley quality and beet and garden bean seed yields.
“We’ve got quite a large area where the district is struggling to produce enough water from the wells,” Harrison said. “They’ve drilled three to five wells there and gone down to 500 feet and found nothing but dust.”
Elliot Traher, NRCS district conservationist for Cassia and Minidoka counties, said projects putting available surface water to better use and turning off wells are becoming increasing common throughout the aquifer.
“We’ve got to look at water conservation in many different areas across the board when it comes to farming,” Traher said. “I think everyone has a certain responsibility for water conservation.”